• Created 2 or more tables in relational model
• Edit table 1's "relational:Native Query" extension property (SELECT * FROM FOOBAR)
• Save
• Open/Select Table Editor and select BASE TABLES tab
• Note that "relational:Native Query" property is same for both tables

Looks like the ModelExtensionPropertyDescriptor is caching an EObject and the call to getPropertyValue() will return the same value for ALL EObjects rather than having a unique EObject per descriptor